Messages in this thread | | | Date | Mon, 30 May 2011 22:05:38 -0700 (PDT) | From | David Rientjes <> | Subject | Re: IrDA driver fails on PXA255 |
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On Sun, 29 May 2011, Russell King - ARM Linux wrote:
> > That would return memory that is not guaranteed to be within the first > > 16MB of address space, so a GFP_DMA allocation would succeed with memory > > not from ZONE_DMA. > > Err, no. GFP_DMA returns memory in a zone which the platform has setup. > There's nothing specific about it being "16MB" or any other size; the > arch can chose what size that is. >
Sorry, was talking from the x86 perspective, which probably doesn't make much sense since we're talking about an arm driver :)
> > That's an invalid configuration, so users, including > > you, should at least edit their .config by hand to enable CONFIG_ZONE_DMA > > as a workaround. > > Again, no. This change has caused a load of previously working drivers > to suddenly start failing without _any_ explanation why or even warning > about the change. It needs to start off as a WARN_ON() so that stuff > can be fixed, and then changed to a hard error. >
I haven't seen a "load" of error reports where this is causing an issue, maybe it is much more popular on arm?
This also isn't a hard error, admins should be able to enable CONFIG_ZONE_DMA and rebuild so that the driver being loaded can get the type of memory it is requesting. Just putting a WARN_ON() doesn't provide any incentive to ever get this stuff fixed.
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